It’s Spring!

Daily Archives: March 20, 2014

Today is the March Equinox. Finally! The equinox occurred at 16:57 UTC.

For me, the winter has been long and cold, March alone has been 12 oC below normal. In fact it is still cold. Maple syrup producers have hardly made a drop so far.

A cartoon depicting the angle of sunlight lighting the Earth’s surface. Image by Przemyslaw “Blueshade” Idzkiewicz.

So the March equinox heralds longer days for the northern hemisphere and shorter days for the south. On the day of the equinox the tilt of the Earth is more or less balanced as you can see in the cartoon above.

Most of you have no doubt noticed the date of equal and night does not necessarily occur on the equinox (today for example). The day that comes the closest to 12 hours day and night depends on your latitude. For my latitude (~45 N) that day was this past Monday. Here is a good explanation of why.

The image below attempts to show this day length / latitude relationship, and while it isn’t down to the minute or anything, it depicts how things progress during the year. That and I liked it.

Amount of daylight through the year at different latitudes. Image: Creative Commons